Recent studies of the $\Lambda (1520)$ resonance within chiral unitary theory with coupled channels find the resonance as a dynamically generated state from the interaction of the decuplet of baryons and the octet of mesons, essentially a quasibound state of $\pi {\Sigma }^{*}(1385)$ in this case, although the coupling of the $\Lambda (1520)$ to the $\overline{K}N$ and $\pi \Sigma$ makes this picture only approximate. The $\pi {\Sigma }^{*}(1385)$ decay channel of the $\Lambda (1520)$ is forbidden in free space for the nominal mass of the ${\Sigma }^{*}(1385)$, but the coupling of the π to ph components in the nuclear medium opens new decay channels of the $\Lambda (1520)$ in the nucleus and produces a much larger width. Together with medium modifications of the $\overline{K}N$ and $\pi \Sigma$ decay channels, the final width of the $\Lambda (1520)$ at nuclear matter density is more than five times bigger than the free one. We perform the calculations by dressing simultaneously the $\Lambda (1520)$ and the ${\Sigma }^{*}(1385)$ resonances, finding moderate changes in the mass but substantial ones in the width of both resonances.

• Received 27 November 2005

DOI:https://doi.org/10.1103/PhysRevC.73.045213